Endangered Species in the Pacific Islands

Recovery Plan for the Caesalpinia kavaiensis & Kokia drynariodes

C. kavaiensis also known as Uhiuhi is a medium-sized tree up to 35 feet (10 meters) tall with rough, dark bark and a spreading crown. The wood is highly valued for its color, grain and density. Early Hawaiians took advantage of the wood's high density to make a fishing implement that sinks rather that floats. About 50 individuals of C. kavaiensis are known on the islands of Hawai‘i, O‘ahu, and Lana‘i, as od 2010. It was once found also on Maui and Kaua‘i but is now believed to be extirpated on those islands.

Uhiuhi - Photo credit Marie Bruegmann/USFWS

K. drynariodesis also known as Hau hele ‘ula or koki‘o is a small tree, 13 to 35 feet (4 to 10 meters) tall and with a trunk up to 8 inches (20 centimeters) in diameter. The showy flowers and bracts and the attractive star-shaped leaves give it an appealing appearance, and it is sometimes used as a garden and ornamental plant. Only 5 wild individuals of K. drynariodes are known from the North Kona district on the island of Hawai‘i. K. drynariodes is not reproducing in the wild, and only limited reproduction of C. kavaiensis is occurring.

Hau hele ‘ula - Photo credit Marie Bruegmann/USFWS

Habitat & Distribution:C. kavaiensis occurred on dry leeward portions of 5 of the main Hawaiian Islands. It was first discovered on Kaua‘i by Horace Mann, Jr., around 1864. The relatively late discovery of this species on the various islands implies that it probably was never abundant in the past 200 years.

K. drynariodes is found only on the island of Hawai‘i and was first collected by David Nelson during Captain James Cook's third voyage to the Hawaiian Islands in the 1800s. Collectors in the early 1900s declared this tree to be "exceedingly rare." The only known wild population of this tree is found in a dry forest restoration site in North Kona, near the area designated as critical habitat.

Currently, wildfire threatens the remaining trees of the North Kona populations. Fountain grass (Pennisetum setaceum), an alien plant, now covers the once-barren lava substrate, fueling wildfires where previously none burned and competing with native tree seedlings for light and water. In addition, C. kavaiensis is heavily threatened by black twig borer, for which there is currently no easily applicable control method.

Recovery:
Most of the few remaining wild trees of both species are growing in severely degraded habitat in dry forest on the slopes of Hualalai volcano in North Kona on the island of Hawai‘i.

The number of surviving trees have been reduced over the past 2 centuries by the browsing of domestic cattle and feral animals, the introduced black twig borer, and fire. Browsing has prevented the growth and establishment of young trees.

C. kavaiensis was listed as endangered by the U.S. Fish and Wildlife Service in 1986 and K. drynariodeswas listed with critical habitat designation in 1984. The State Department of Forestry and Wildlife actively manages part of the habitat of the remaining wild trees.

Management goals include reduction of the threats of fire and damage by animals, habitat improvement to encourage natural regeneration, and outplanting nursery-raised trees. Private landowners have taken some steps to protect and manage endangered species on leased lands.